机械振动应力下IMU内MEMS传感器的抗振研究

Research on anti-vibration of MEMS sensor in IMU under mechanical vibration stress

针对惯性测量单元(IMU)内部微机电系统(MEMS)传感器粘固在印刷电路板(PCB)上,外界载体产生的机械振动使其受迫振动,长时间作用会引发传感器机械疲劳、结构断裂以及性能退化等问题,根据结构动力学原理,分析双自由度系统模型,并运用MATLAB软件进行仿真,以找出影响因素及其设定范围;同时,保证在加速度计带宽范围内的信号1︰1传递给加速度计。研究结果表明:载体机械振动信号在10 kHz范围内时,适当降低陀螺仪和加速度计的品质因数,PCB的固有频率保持在1kHz以内以及其品质因数不大于10,可有效降低振动应力对传感器的影响。

Aiming at the problem that micro-electro-mechanical system( MEMS) sensor is stuck on PCB in inertial measurement unit( IMU),the mechanical vibration generated by external carrier is forced to vibrate,longterm effects can cause problems such as mechanical fatigue,structural fracture,and performance degradation of the sensor,according to the principle of structural dynamics,the two-degree-of-freedom system model is analyzed,and the simulation is performed by MATLAB software to find out the influencing factors and their setting range. At the same time,the signal transmitted to the accelerometer by 1︰1 within the accelerometer bandwidth is guaranteed.The research results show that when the mechanical vibration signal of the carrier is in the range of 10 kHz,appropriately reduce the quality factor of the gyroscope and the accelerometer,natural frequency of the PCB is kept within 1 k Hz and the quality factor is not more than 10,which can effectively reduce the influence of vibration stress on the sensor.